Nanohardness measurements performed in an SFM (Scanning Force Microscope) are compared with macrohardness data obtained by conventional means. Nanohardness provides detailed information about material hardness on a sub-micron length scale, contributing valuable insights on commutator and brush wear in a fuel pump wear simulation test. For a commutator material consisting of a harder component dispersed in a softer matrix, nanohardness measurements show the hardness of both components. The observed rates of brush wear cannot be explained satisfactorily without this additional nanoscale information. SFM nanohardness measurements are expected to prove useful in a variety of tribological systems.